Access status: Open Access ,
Modelling of amplitude-selective-damping valves
(2011) Gołdasz, Janusz P.
The so-called amplitude-selective-damping (ASD) valving is a relatively new approach for modifying the output of a hydraulic shock absorber. In the automotive industry ASD valves are known to improve isolation from road inputs. During more aggressive maneuvers the systems maintains the performance of a standard (non-ASD) shock absorber. In the paper, the author derives and analyzes a fairly complete state-space model of an exemplary piston-side ASD valve. The model includes key geometric and performance characteristics of the valve. The results are shown in the form of phase plane plots of force-displacement diagrams, respectively, for a twin-tube shock absorber configuration of choice.
Access status: Open Access ,
Wyznaczanie położenia konturów złożowych dla złóż ropy naftowej i gazu ziemnego w oparciu o kryteria hydrodynamiczne
(2005) Wojna-Dyląg, Elżbieta; Zawisza, Ludwik
The size and shape of a hydrocarbon field are determined by geological boundaries of strata and surface of the contour. The location of contours depends on the flow of formation waters, reservoir properties of rocks and properties of reservoir fluids. The mapping method of hydrodynamic hydrocarbon traps presented in this paper to determine the site of the field contour and so the deposit boundaries for oil and natural gas. To define the field contours it is necessary to work out a structural map of water-oil-bearing horizon, potentiometric map for reservoir water, map of specific gravity for reservoir water, map of specific gravity of oil in reservoir conditions, map of porosity, map of permeability and map of capillary pressures. Then the methodics presented in the paper should be applied. The procedure lies in performing some simple algebraic operations on maps. The realization of the discussed methodics is presented on the example of the oil field Czerwieńsk, in the Main Dolomite strata in the Fore-Sudetic area.
Mechanics and Control
2015 - Vol. 34 - No. 4
Access status: Open Access ,
Active control of vibrations of a three-axis gyroscopic platform on board of a flying object
(Wydawnictwa AGH, 2005) Koruba, Zbigniew; Styczeń, Jerzy
The work presents an algorithm for active control of vibrations of a three-axis gyroscopic platform during pre-programmed and stabilised operation on board of a flying object. The considerations focus on disturbances resulting from the flying object manoeuvres and short-duration pulses of external forces under the conditions of friction in the bearings and non-linear platform operation range.
Access status: Open Access ,
Automatyczna detekcja elementów asymetrii w dynamicznych mapach CBF perfuzji mózgowej
(Wydawnictwa AGH, 2008) Hachaj, Roman
This paper presents a new algorithm that enables detection of asymmetry in dynamic CBF perfusion maps. In the first stage of the algorithm detection of symmetry axis of image (between left and right hemisphere) is performed. In the second stage the level of asymmetry in cerebral blood flow is measured by detection of regions with different perfusion in both brain hemispheres. The algorithm was tested on a set of 28 different images showing or not cerebral blood flow anomalies. The paper also describes the method for estimating cerebral blood flow with a non diffusing contrast agent based on the Meier-Zierler convolution model as well as CBF, CBV, MTT and TTP perfusion maps.
Access status: Open Access ,
Sylikatowe żywice organiczno-mineralne w budownictwie podziemnym i tunelowym
(2007) Stachoń, Witold; Chmura, Janusz
Organic-mineral silicate resins are a specific group of the injection-media widely at present used in underground construction and tunnelling. Their common feature is the water environment has no influence on the course of the reaction. The distinction between them and the polyurethane resins (PUR) is they do not transfer the flame and belong to the group of self-extinguishing resins. Both the characterization and examples of the use of organic-mineral silicate resins have been given in the paper.
Access status: Open Access ,
Wiarygodność korelacji magnetostratygraficznych na lokalnym przykładzie z wapieni oksfordu w Gnieździskach (Góry Świętokrzyskie)
(Wydawnictwa AGH, 2008) Lewandowski, Marek; Sidorczuk, Magdalena; Ziółkowski, Piotr
Access status: Open Access ,
Badania wpływu nowo opracowanych płuczek kationowo-skrobiowych na zmianę przepuszczalności ośrodka przy użyciu filtrów ceramicznych
(2007) Wysocki, Sławomir; Bielewicz, Danuta; Wysocka, Marta
In this paper results of investigations of new drill-in muds with cationic polymers are presented. Rheological properties and influence onto permeability of rocks were research. Investigations were moved in simulated downhole conditions. In tests dynamic HPHT filter press and ceramic filters (as a rock simulator) were used. Research shoved, that new cationic-starch drill-in muds couse smaller permeability damage than mud used in Polish industry.
Access status: Open Access ,
Investigations of influence of vibration on human-operator control functions
(2010) Basista, Zygmunt; Książek, Marek A; Tarnowski, Janusz
In the paper results of experimental investigations of the system operator-handle-base have been presented. The aim of investigations was to record and analyse dynamical reactions of human operator volunteers participating in the experiments on a visual, suddenly appearing step signal. The main task of each operator was tracking of the signal as precisely as possible with a push force exerted on the tool handle. The measurements were done on an especially designed stand. The stand allows to simulate vibration of the tool with chosen frequencies with or without handle isolation. Time histories of step reference and forces realized by the operator were statistically elaborated and graphically presented.
Metallurgy and Foundry Engineering
2017 - Vol. 43 - No. 2
Access status: Open Access ,
Mineralogical investigation of selected phenomenon present in Kom C, Tell el-Farcha archaeological site, the Nile Delta, Egypt
(2010) Pawlikowski, Maciej ; Strzelczyk, Jacek
Investigation of selected samples collected coming from Kom C at Tell el Farcha site were performed using various mineralogical methods. Examination were conducted in order to identify substances as well as to explain their origin. Samples represent material filling up old fireplaces, mineralized charcoal and organic mat, dark substances coating alabaster vessels and other. Determination of the mentioned substances and samples help to understand the life in the past better.
Access status: Open Access ,
Regulacja procesu spalania z wykorzystaniem SSN oraz algorytmów ewolucyjnych
(Wydawnictwa AGH, 2008) Kalita, Mariusz; Wójcik, Waldemar
The paper presents simulation of applying evolutionary algorithms and neural networks in power boiler process regulation. The various methods of selection, niche mechanism and coupling methods are presented in the paper. The results show that implementing proper selection operator and niche mechanism allow to prevent premature convergence and reduce computation time.
Access status: Open Access ,
Mineralogical and petrographical investigation of sediments from the Tell el Farkha archaeological site, the Nile Delta, Egypt
(2016) Słowioczek, Edyta
W trakcie badań w pierwszym etapie skoncentrowano się na badaniach terenowych. Sporządzono generalny profil geologiczny oraz pobrano próbki konieczne do badań laboratoryjnych. W następnym etapie wykonano analizy laboratoryjne. Przy pomocy lupy binokularnej przyjrzano się drobnym frakcjom pochodzącym z rozlasowania fragmentów próbek z profilu. Potem przeprowadzono badania mineralogiczno-petrograficzne cegieł suszonych. Obejmowały one określenie składu mineralnego i ziarnowego próbek z cegieł jasnych i ciemnych. Później zajęto się badaniami antropogenicznych węgli. Celem analizy było określenie ich właściwości sorpcyjnych. Na zakończenie zaprezentowano wyniki badań, w których zawarto szkice, fotografie, mikrofotografie, tabele i diagramy oraz dokonano podsumowania badań i przedstawiono wnioski, jakie można z nich wyciągnąć. Powstanie pracy pozwoliło na rozwiązanie ciekawych problemów z pogranicza mineralogii, geologii i archeologii. Wszystkie przeprowadzone badania mają charakter nowatorski i wnoszą dużą ilość nowych i istotnych informacji pozwalających poznać stanowisko oraz aktywność ludzi przed tysiącami lat.
Access status: Open Access ,
New concept of ECT/ERT/GRT tomography for multiphase flow measurements
(Wydawnictwa AGH, 2010) Nowakowski, Jacek; Hammer, Erling; Sankowski, Dominik; Styra, Darius; Wajman, Radosław; Banasiak, Robert; Romanowski, Andrzej
The multiphase flow measurements are very important tasks in many areas of industrial processes applications. One of them is undersea exploration of oil in the petroleum industry. The submitted paper presents application of multi modality: capacitance, impedance and gamma ray tomography for performing measurements of a flow composed of sea water, oil and gas flow, theoretical principles applied to design multimodality tomograph and results of experiments performed in University of Bergen. The experiments were done using ECRT tomograph designed and built in Technical University of Lodz and combined measurements of signals acquired from all measuring modalities. Measurement confirmed that multi modality approach allows to give fast and reliable on-line results of measurements of composition of multi phase flow. Applied algorithm allowed to speed up on-line measurements and presented results in a form required in industrial applications. The derived conclusions can be used as a guidelines for preparation of industrial applicable construction of tomograph.
Access status: Open Access ,
Techniques of neural networks for signal parameterization used in monitoring systems
(Wydawnictwa AGH, 2008) Wszołek, Wiesław
The paper presents selected aspects of research concerning a new concept in application of computer technology to the analysis of acoustic signal. This new concept assumes, that during the analysis of signal the study is not focused on determining some or other signal parameters, neither it is focused on the signal classification, but it is supposed to lead to an automated understanding of the origins of the deformation, which can be revealed in analyzed signal.
Access status: Open Access ,
Iniekcyjne wzmacnianie górotworu podczas przebudów wyrobisk korytarzowych jako sposób zapobiegania obwałom skał i skutkom tych obwałów
(Wydawnictwa AGH, 2005) Rembielak, Tadeusz; Mielniczuk, Lech; Rosikowski, Janusz; Rusinek, Józef; Wala, Franciszek
The occurring mineral water in KWK »Piast« cause a corrosion of the excavations lining. Because of that it is necessary to rebuild these dog headings. In order to increase safety during rebuilding crossing of excavations there were applied forthcoming injectory firming of the rock mass in its surrounding, which prevents from occurring the fall of rocks and from the results of these fallings. In the paper there was presented an example of crossing rebuilding technology from a lining LP to the crossing of the POLYTRAB type in the Heintzmann Company in KWK »Piast«.
Access status: Open Access ,
Zmienność litologiczna osadów ilasto-krzemionkowych z obszaru IOM (strefa rozłamowa Clarion-Clipperton; E Pacyfik)
(Wydawnictwa AGH, 2011) Maciąg, Łukasz; Kotliński, Ryszard A.; Borówka, Ryszard K.
Authors presented geospatial variability of selected sedimentological, mineralogical and diagenetical features of clayey-siliceous sediments from Interoceanmetal deposit area (eastern Pacific, Clarion-Clipperton fracture zone). Changes of environmental conditions essential to geological and palaeogeographical situation into C-C zone, and also their importance to forming processes of Fe/Mn oxide concentrations have been described. Research studies on sediments, classified to the uppermost part of Clipperton FCl IV Formation (pliocene-holocene), show unimodal distribution of samples, poor sorting and mean grain size of siliceous clayey muds amount to x = 6,83 phi. Some qualitative/quantitative changes into the mineral composition of the clay 0,004 / 0,002 mm subfractions (clay minerals from kaolinite/illite/chlorite/smectite groups), perpendicular variability of some Radiolaria/Diatomeae species and also micronodules amount depletion during burial processes have been confirmed. Environmental conditions into the C-C zone enable to form economically attractive depositional fields covered by polymetallic nodules that constitute potential ore sources of Mn, Ni, Co, Cu and other metals in the future.
Access status: Open Access ,
Sonda wkręcana WST w badaniach mioceńskich iłów krakowieckich
(Wydawnictwa AGH, 2010) Olesiak, Sebastian
Polish Standards concerning field investigations with application of (among others) Swedish Weight Sounding (SWS) probe gives an interpretation of results only for non cohesive soils. Scarcity of results interpretation for non cohesive soils to some extent disqualifies this tool for estimation of strength parameters of those soils. Present paper shows a proposal of interpretation of SWS probe measurement results for Miocene krakowieckie clays. The paper can be a base for future, full interpretation of cohesive soils measurement with application of SWS probe and can be useful during works in next years on Polish Standards.
Access status: Open Access ,
PDC single cutter : the effects of depth of cut and RPM under simulated borehole conditions
(2011) Majidi, Reza; Miska, Stefan; Tammineni, Sandeep
While the weight on bit (WOB) and rotary speed (RPM) are perhaps the most important drilling parameters affecting the rate of penetration, limited information are available about the fundamental mechanisms of rock destruction and the effect of cutting speed and the depth of cut during the cutting process. Experiments were carried out in a high-pressure facility with a 13 mm single PDC cutter to cut Carthage Marble and Indiana Limestone samples with depths of cut in the range of 0.02-0.12 inch and rotary speeds from 30 to 180 RPM at atmospheric and pressurized conditions. Our previous experimentations showed that an increase in the confining pressure as small as 150 PSI could significantly increase the Mechanical Specific Energy (MSE) of the cutting process and reduce the efficiency by half. Recently performed atmospheric and pressurized single cutter tests, showed that a minimum depth of cut was required to efficiently drill the rock samples. MSE required to cut the rock, reached a minimum at depths of cut greater than 0.08 inches for both Indiana Limestone and Carthage Marble samples. Most promising were the results that showed a decrease in MSE at high rotational speeds (RPM 100) and atmospheric pressure, possibly indicating a change in rock failure mechanism. A mathematical model was derived from the balance of forces acting at the PDC cutter that constitutes a single linear relation between the cutting force and the normal force. The characteristic line acts as an indication of bit-rock interaction and can be used to detect the formation and cutter dullness. The model was verified using the experimental data from the single cutter tests. Such observations and analysis provide useful insights into the physics of cutter-rock interaction and are valuable to the improvements of drilling practices selection (WOB, rotary speed, etc) and the rates of penetration.
Access status: Open Access ,
Technological and safety aspects of CNG home fast refueling units
(2016) Kuczyński, Szymon; Liszka, Krystian; Łaciak, Mariusz; Olìjnik, Andrìj; Strods, Robert; Szurlej, Adam
Despite all global economic shifts and the fact that natural gas is recognized worldwide as the main and the leading alternative to oil products in transportation sector, there is a huge barrier to switch passenger vehicle segment to natural gas – the lack of refueling infrastructure for natural gas vehicles. The key to solving that problem and providing barrier breaking refueling infrastructure solution for natural gas vehicles (NGV) is home fast refueling units. It operates using natural gas (methane), which is being provided through gas pipelines at client’s home, and electricity connection point. It enables an environmentally friendly NGV’s home refueling just in minutes. The underlying technology is one stage hydraulic compressor (instead of multistage mechanical compressor technology) which provides the possibility to compress low pressure gas from residential gas grid to 200 bar for its further usage as a fuel for NGVs. More than efficiency and convenience, the direct hydraulic compressor technology provides compelling cost and lifetime advantages as well as superior convenience over other solutions. Aims of this article is to compare technical, technological and safety aspects of home refueling units and estimate a perspectives of natural gas vehicles as an alternative for regular vehicles.